BACKGROUND: Interest in lycopene is growing rapidly following the recent publication of epidemiologic studies in which high circulating lycopene concentrations were associated with reductions in cardiovascular disease. Lycopene is one of the major carotenoids in the Western diet and is probably one of the protective factors in a vegetable-rich diet. OBJECTIVE: We studied the hypothesis that the intima-media thickness of the common carotid artery (CCA-IMT) would be greater in men with low serum lycopene concentrations. DESIGN: We investigated the relation between serum lycopene concentration and CCA-IMT in 1028 middle-aged men (aged 46-64 y) in eastern Finland who were participants in the Kuopio Ischaemic Heart Disease Risk Factor study and who were examined in 1991-1993. The subjects were classified into quarters according to serum lycopene concentration. RESULTS: In a covariance analysis with adjustment for covariates, the men in the lowest quarter of serum lycopene concentration had a significantly higher mean CCA-IMT and maximal CCA-IMT (P = 0.005 and P = 0.001 for the difference, respectively) than did the other men. The mean and maximal CCA-IMT increased linearly across the quarters of serum lycopene concentration. CONCLUSIONS: A low serum lycopene concentration is associated with a higher CCA-IMT in middle-aged men from eastern Finland. This finding suggests that the serum lycopene concentration may play a role in the early stages of atherosclerosis. Increased thickness of the intima-media has been shown to predict coronary events; thus, lycopene intakes and serum concentrations may have clinical and public health relevance. Rissanen TH, Voutilainen S, Nyyssonen K, Salonen R, Kaplan GA, Salonen JT. Am J Clin Nutr 2003 Jan;77(1):133-8.